Made of high-tech proprietary glass filled nylon RX. Provides better impact resistance than standard glass filled nylon. Does not absorb moisture like phenolic, and offers better floor preservation than steel or cast iron. Resists most chemicals, solvents, gases, acids and steam cleaning. Top plate measures 4 x 4 1/2″. Black tread color. 85 (+/-5) Shore D. wheel core material is glass filled nylonRX.
